Various types of foamed plastic products are known and many of these products are produced by an extrusion process and produce a body portion which is relatively soft and resilient. Foamed polyethylene extruded products have been used for pipe insulation and have also been applied about structural members to provide a resilient outer cushion member. For example, foamed polyethylene cushion members have been applied to supports of gymnastic equipment, playground equipment, football standards and basketball poles to reduce the possibility of injury by striking of the structural member.
Foamed polyethylene can be extruded in a number of different shapes and is very valuable for the type of applications described above. Unfortunately, the product is relatively soft, and thus, the outer surface can tear easily, even though there is a very thin skin portion produced at the outer surface of the product during the extrusion process. To overcome this problem, fabric or tape have been applied about the product, and thus, provides a further surface which protects the underlying polyethylene from damage.
It would be desirable to have a foamed polyethylene product which has a tougher outer surface and one which can be produced in a cost effective manner.
Some solutions to the above problem have been proposed and one such solution involves using a separately foamed cylindrical sheath, which when exposed to heat shrinks about a product. The outer sleeves are placed about a polyethylene foamed product and then heat is applied to the sheath which then contracts to the diameter of the foamed polyethylene. This results in a two-stage process to marry the polyethylene foamed body and the outer sheath and it also requires somehow placing the foamed polyethylene body within the outer sheath. Examples of these types of structures and other arrangements are disclosed in U.S. Pat. No. 3,607,497, U.S. Pat. No. 3,813,272, U.S. Pat. No. 3,832,260, United 10
U.S. Pat. No. 4,634,615, U.S. Pat. No. 4,776,803, U.S. Pat. No. 4,780,158, U.S. Pat. No. 4,861,412, U.S. Pat. No. 4,950,352 and U.S. Pat. No. 5,360,048.
The present invention seeks to address the problems outlined above and produce a product which can be produced at a lower cost.